The roast was 4.77 lbs.  I went according to Tim/Kenji's chart:
Quote:
Place in oven and cook until center of roast registers 120°F on an instant-read thermometer for medium-rare, or 135°F for medium. In a 150°F oven, this will take around 5 1/2 to 6 1/2 hours. In a 200°F oven, this will take 3 1/2 to 4 hours.
My oven may need calibrating (it's fairly new) it said 150 and according to therm/probe, roast turned 120  around 11:00 a.m.  I pulled it, tented it until I was ready to serve, as instructed, and then seared it.  It was perfect.